tatsuyasusukida · May 16, 2025 02:36 · tatsuyasusukida · May 16, 2025
diff --git a/!README-javascript-media-video.md b/!README-javascript-media-video.md
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>How to record a video with JavaScript</title>
  </head>
  <body>
    <div>
      <button type="button" id="buttonStart">Start</button>
      <button type="button" id="buttonStop" disabled>Stop</button>
    </div>
    <div>
      <video autoplay muted playsinline id="videoLive"></video>
    </div>
    <div>
      <video controls playsinline id="videoRecorded"></video>
    </div>
    <script src="main.js"></script>
  </body>
 </html>
diff --git a/LICENSE b/LICENSE
 MIT License

 Copyright (c) 2025 Tatsuya Sususkida

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
diff --git a/main.js b/main.js
 async function main () {
  const buttonStart = document.querySelector('#buttonStart')
  const buttonStop = document.querySelector('#buttonStop')
  const videoLive = document.querySelector('#videoLive')
  const videoRecorded = document.querySelector('#videoRecorded')

  const stream = await navigator.mediaDevices.getUserMedia({ // <1>
    video: true,
    audio: true,
  })

  videoLive.srcObject = stream

  if (!MediaRecorder.isTypeSupported('video/webm')) { // <2>
    console.warn('video/webm is not supported')
  }

  const mediaRecorder = new MediaRecorder(stream, { // <3>
    mimeType: 'video/webm',
  })

  buttonStart.addEventListener('click', () => {
    mediaRecorder.start() // <4>
    buttonStart.setAttribute('disabled', '')
    buttonStop.removeAttribute('disabled')
  })

  buttonStop.addEventListener('click', () => {
    mediaRecorder.stop() // <5>
    buttonStart.removeAttribute('disabled')
    buttonStop.setAttribute('disabled', '')
  })

  mediaRecorder.addEventListener('dataavailable', event => {
    videoRecorded.src = URL.createObjectURL(event.data) // <6>
  })
 }

 main()
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>How to record a video with JavaScript</title>
	</head>
	<body>
	<div>
	<button type="button" id="buttonStart">Start</button>
	<button type="button" id="buttonStop" disabled>Stop</button>
	</div>
	<div>
	<video autoplay muted playsinline id="videoLive"></video>
	</div>
	<div>
	<video controls playsinline id="videoRecorded"></video>
	</div>
	<script src="main.js"></script>
	</body>
	</html>
	MIT License

	Copyright (c) 2025 Tatsuya Sususkida

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	SOFTWARE.
	async function main () {
	const buttonStart = document.querySelector('#buttonStart')
	const buttonStop = document.querySelector('#buttonStop')
	const videoLive = document.querySelector('#videoLive')
	const videoRecorded = document.querySelector('#videoRecorded')

	const stream = await navigator.mediaDevices.getUserMedia({ // <1>
	video: true,
	audio: true,
	})

	videoLive.srcObject = stream

	if (!MediaRecorder.isTypeSupported('video/webm')) { // <2>
	console.warn('video/webm is not supported')
	}

	const mediaRecorder = new MediaRecorder(stream, { // <3>
	mimeType: 'video/webm',
	})

	buttonStart.addEventListener('click', () => {
	mediaRecorder.start() // <4>
	buttonStart.setAttribute('disabled', '')
	buttonStop.removeAttribute('disabled')
	})

	buttonStop.addEventListener('click', () => {
	mediaRecorder.stop() // <5>
	buttonStart.removeAttribute('disabled')
	buttonStop.setAttribute('disabled', '')
	})

	mediaRecorder.addEventListener('dataavailable', event => {
	videoRecorded.src = URL.createObjectURL(event.data) // <6>
	})
	}

	main()